Simple AWS DynamoDB driver for nodejs

Simple Node.js DynamoDB driver to perform basic CRUD operations, it is meant to be as simple as possible.

Installation

npm i dynamodb-driver

Initialisation

varDDbDriver=require("dynamodb-driver"),table=DDbDriver(awsConfigObject,DynamoDbConfigObject);

Example

vartable=DDbDriver({region: "eu-west-1"// --- your AWS config object if need be (AWS.config.update(awsconfig));},{dynamodb: '2012-08-10'});

Create row

Creates a row in the specified table, and id will be automatically generated using shorId if non exists in the document Returns a promise resolving a document that has just been created

Usage

somePromise=table.create(tableName,documentToCrate);

Example

table.create("Users",{firstName: "Marilyn",lastName: "Manson",active: true}).then(function(user){// user is something like{
id : "S1KtimR6"
firstName: "Marilyn",lastName: "Manson",active: true}});

Update row

Usage

somePromise=table.update(tableName,documentToUpdate[,conditions][,keys]);

conditions: An object with a ConditionExpression and a ExpressionAttributeValues (See: http://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_UpdateItem.html)

keys: Should you table is not using id as primary key, you can specify your primary and sort key here such as ["organisationId", "documentId"]

Conditional write

Specify a value within brackets with an exclamation mark to perform an update only if the value doesn't exist

{id: "S1KtimR6",creationDate: "[!"+newDate().getTime()+"]"}

Increment

Specify a value within brackets with ++ to perform an increment by one of the existing value

{id: "S1KtimR6",count: "[++]"}

Decrement

Specify a value within brackets with -- to perform a decrement by one of the existing value

{id: "S1KtimR6",count: "[--]"}

Example

table.update("Users",{id: "S1KtimR6",isPowerUser: true},{ConditionExpression: "active = :active",ExpressionAttributeValues: {":active": true}}).then(function(user){// user would be something like that{
id : "S1KtimR6"
firstName: "Marilyn",lastName: "Manson",active: true,isPowerUser: true}});

Query rows

Usage

somePromise=table.query(tableName,query[,indexName][,options]);

query:

• could be an array for the query with the key, ComparisonOperator and AttributeValueList for legacy KeyConditions.
• could be an object with a KeyConditionExpression and ExpressionAttributeNames

Example

// Using the legacy KeyConditions modetable.query("Users",[{key: "email",operator: "EQ",value: email},{key: "password",operator: "EQ",value: password}],"EmailPasswordIndex").then(function(users){// users is an Array of users[{id: "S1KtimR6",firstName: "Marilyn"lasName: "Manson",active: true,isPowerUser: true},{id: "Z1et9rR5",firstName: "Amaia"lasName: "Albistur",active: true,isPowerUser: false}]});

Get row by Key

Usage

somePromise=table.get(tableName,id);

Example

table.get("Users","Z1et9rR5").then(function(user){// user is something like that{id: "Z1et9rR5",firstName: "Amaia"lasName: "Albistur",active: true,isPowerUser: false}});

Get multiple rows by Key

Usage

somePromise=table.getItems(tableName,arrayOfIds[,options]);

arrayOfIds: An array of ids to retrieve, or an array of objects containing the partition and sort key of the items to retrieve

options: is an optional object
options.consistentRead: true or false, will apply strongly consistent reads instead of the default setting (eventually consistent reads)
options.keys: an array of 1 or 2 strings defining the partition and sort keys

Example

table.getItems("Users",["Z1et9rR5","S1KtimR6"],{consistentRead: true}).then(function(users){// users is an Array of users[{id: "S1KtimR6",firstName: "Marilyn"lasName: "Manson",active: true,isPowerUser: true},{id: "Z1et9rR5",firstName: "Amaia"lasName: "Albistur",active: true,isPowerUser: false}]});

Delete row

Usage

somePromise=table.remove(tableName,id);

Example

table.remove("Users","Z1et9rR5").then(function(user){// user is{id: "Z1et9rR5",firstName: "Amaia"lasName: "Albistur",active: true,isPowerUser: false}});

Delete multiple rows by Key

Usage

somePromise=table.removeItems(tableName,arrayOfObject[,keys]);

keys: when not using id as a primary, you must specify the HASH and optionally RANGE key

Example

table.removeItems("Users",[{id: "S1KtimR6"},{id : "Z1et9rR5"}]).then(function(users){// users is an Array of users[{id: "S1KtimR6",firstName: "Marilyn"lasName: "Manson",active: true,isPowerUser: true},{id: "Z1et9rR5",firstName: "Amaia"lasName: "Albistur",active: true,isPowerUser: false}]});

List rows

Usage

somePromise=table.list(tableName[,query,options]);

Will perform a scan operation on the selected table

query: A specific query array to filter data against options: An object with paginate property as number. It will recursively fetch batches of paginate value until all data has been fetched for this query (note, no exponential backing off)

Example

table.list("Users",[{key: "isPowerUser",operator: "EQ",value: true}],{paginate: 10// Will retieve all data by batches of 10}).then(function(users){// users is an Array of users[{id: "S1KtimR6",firstName: "Marilyn"lasName: "Manson",active: true,isPowerUser: true},{id: "X1ttUU45",firstName: "Francis"lasName: "Kuntz",active: true,isPowerUser: true}]});